From owner-freebsd-stable@FreeBSD.ORG Fri Feb 12 18:31:13 2010 Return-Path: Delivered-To: freebsd-stable@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 315E51065670 for ; Fri, 12 Feb 2010 18:31:13 +0000 (UTC) (envelope-from korvus@comcast.net) Received: from mx04.pub.collaborativefusion.com (mx04.pub.collaborativefusion.com [206.210.72.84]) by mx1.freebsd.org (Postfix) with ESMTP id F40A38FC1B for ; Fri, 12 Feb 2010 18:31:12 +0000 (UTC) Received: from reflector.ws.pitbpa0.priv.collaborativefusion.com ([206.210.89.202]) by mx04.pub.collaborativefusion.com (StrongMail Enterprise 4.1.1.4(4.1.1.4-47689)); Fri, 12 Feb 2010 13:53:31 -0500 X-VirtualServerGroup: Default X-MailingID: 00000::00000::00000::00000::::321 X-SMHeaderMap: mid="X-MailingID" X-Destination-ID: freebsd-stable@FreeBSD.org X-SMFBL: ZnJlZWJzZC1zdGFibGVARnJlZUJTRC5vcmc= Message-ID: <4B759E70.4030809@comcast.net> Date: Fri, 12 Feb 2010 13:31:12 -0500 From: Steve Polyack User-Agent: Mozilla/5.0 (X11; U; FreeBSD amd64; en-US; rv:1.9.1.7) Gecko/20100211 Thunderbird/3.0.1 MIME-Version: 1.0 To: freebsd-stable , freebsd-fs@freebsd.org Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Subject: ZFS ARC being limited below what is defined in /boot/loader.conf X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 12 Feb 2010 18:31:13 -0000 Has anyone had an issue with the ZFS ARC max being limited below what has been defined in /boot/loader.conf? I just upgraded the RAM in a ZFS-equipped system and attempted to devote 4GB to the ARC cache by placing the following in loader.conf: vfs.zfs.arc_max="4096M" However, after rebooting, querying the sysctl gives me this: $ sysctl vfs.zfs.arc_max vfs.zfs.arc_max: 1726489600 or about 1.7GB, an odd number that I can't find any references to. For reference, I'm running 8-STABLE (as of Jan 19th) on an amd64 system with 8GB of RAM. The system was previously very stable with 4GB of RAM and a 512MB arc_max. I have not modified vm.kmem_size_max (defaults to ~330GB on amd64) or any other ZFS tunables. I'd also like to avoid syncing up to the current 8-STABLE if at all possible. Thanks, Steve Polyack